Improvements in instrumentation for energy-dispersive X-ray
microanalysis (EDX) and electron energy-loss spectroscopy (EELS)
have underlined the need for suitable standards for measuring
performance. We report the results from several laboratories
that were supplied with a test specimen consisting of a thin
film of nickel oxide supported on a molybdenum grid. The
Ni-Kα/Mo-Kα count ratio was used as
an indication of number of stray electrons and/or X-rays
in the TEM column; the Ni-Kα peak/background
ratio provided a measure of the total background in the EDX
spectrum, including bremsstrahlung contributions and the effect
of detector electronics. By providing values typical of current
instrumentation, the results illustrate how the test specimen
can be used to evaluate TEM/EDX systems prior to purchase,
during installation, and (periodically) during operation. The
NiO films were also used to test EELS acquisition and
quantification procedures: measured Ni/O elemental ratios
were all within 10% of stoichiometry.